I bought my first sugarglider last night and he is cute, but there are a few things that I would like to know. First, mine has this ball with skin hanging down from his belly,Is that is testicles???? I have seen pictures of sugargliders but never noticed that, Is that normal? Also, he was barking lastnight is he happy when he does that??? Last but not least,he is running all over his cage, he will come to me when I call his name and wants to get out and explore, but I am scared he will run off and get lost...Should I be?